I have been toying with what to do with the Tamiya M-41 I have just bought as well as other existing kits, including a M-10 Wolverine (17pdr) and a M-18 Hellcat I acquired from Old Wombat last Christmas and have come up with what I believe to be a plausible scenario.
Backstory revolves around the (delusional / common sense) decision, spurred by combat experience in WWII and then the Korean conflict, to mechanise the regular army and CMF, including a plan to acquire a suitable platform to replace the various WWII vintage tanks and tank derived armoured vehicles used by the CMF armoured units in real life.
Late war plans for one regular and two reserve tank brigades, each of five regiments, equipped respectively with Centurions and Comets, never eventuated. A single regular tank regiment with Churchills (later replaced with Centurions) was formed from an armoured car Squadron (equipped with Staghound armoured cars), while the various CMF squadrons and regiments were equipped variously with dwindling numbers of M-3 Grants, Matildas, Staghounds and 17pdr AT guns into the 50s. Despite the shock of Korea, that reaffirmed many of the lessons of WWII, Australia continued with the fiction that light or "Jungle" infantry, supported by the bare minimum of armour and artillery, was all that was needed.
My alt history sees the shock of Korea initiate the emergency acquisition of surplus equipment to reequip the CMS armoured and AT units, in addition to the raising of a regular armoured brigade to recast the Australian Regular Army as an Armoured Division instead of just an Infantry Brigade. Key to this plan was the eventual local production of an armoured chassis to re-equip most if not all light and medium armoured units by the early 1960s.
Phase 1 - select and order a modern tank to form the bulk of the planned tank brigade.
Phase 2 - the order of the most suitable surplus equipment available to re-equip existing CMF and remaining regular units. Factors in determining suitability; cost, ease of supporting locally (inc. commonality with existing platforms), reliability and suitability to be modernised for service into the early 60s.
Phase 3 - develop a modernisation plan for the acquired surplus equipment so it can remain effective for a decade. Ensure the modernisation program develops the required knowledge and skills to facilitate the local production of replacement vehicles to enter service from the late 1950s.
Phase 4 - design and introduce into service an armoured, self propelled, tank destroyer / assault gun to replace towed AT guns in the infantry battalions.
Phase 5 - licence produce a modern light AFV family of vehicles (FOV)
Phase 6 - licence produce a modern Universal tank and associated FOV.
Phase 7- modernise the vehicles acquired in Phase 1 for further service in the CMF.
The Phase 1 tank was the British Centurion of the latest mark, intended to equip five regiments.
The acquisition of surplus vehicles in Phase 2 to cover:
A light tank to equip the armys regular cavalry regiment, the cavalry (reconnaissance) squadrons of the CMF and reconnaissance platoons of the armoured and mechanised infantry battalions - M-24 Chaffee
A medium tank to replace the M-3 Grant in the CMF tank units Comet (and maybe M-4 Sherman)
A heavy (or infantry) tank to replace the Matilda in the support company tank platoons of the infantry battalions Churchill VII and VIII (an interim measure as the tank brigade was formed)
A light, turreted tank destroyer to complement the light tanks in the cavalry M-18 Hellcat
A medium, turreted tank destroyer to equip the CMFs AT regiments and independent AT squadrons (replacing the cavalrys towed AT guns) M-10 and M-10C
A heavy, turreted tank destroyer to equip the armys tank destroyer regiment M-36B2 Jackson
25pdr SPG Yeramba (SPG converted from M-3A5 Grant hulls)
A load carrier / tractor supporting mechanised units converted M-3A5 and M-10
Recovery and support versions of major types.
Phase 3 saw the modernisation and standardisation (where possible) of the surplus equipment:
M-10, M-10C, M-36B2, Yeramba and other M-3 conversions were standardised mechanically on the Detroit GM 6-71 and HVSS suspension.
All M-10 and M-18 were standardised on the 17pdr gun, then up gunned again with the 20pdr as the Centurions were converted to 105mm from 1960.
The M-36B2 was fitted with the QF 20pdr in the early 50s, then it in turn was replaced with the L7 105mm from the late 50s.
Comets received minimal modernisations to standardise ancillary equipment where possible while the M-4s received the common drive train and suspension, along with the 77mm HV gun of the Comet.
The remaining Churchills were converted into support vehicles and were replaced within the infantry battalions by light tanks and the new SPG AT.
MGs were standardised on the M-1919 .30cal MMG and the M-2 .50cal HMG
Phase 4 was an indigenous Australian design that looked suspiciously like the late war German E-10 casemate tank destroyer. It was a replacement for the towed 6pdr AT guns and was armed with the 77mm HV from the Comet, it arrival, as well as the light tanks for reconnaissance, allowed the retirement of the Churchill. Working name, Echidna.
Phase 5 was the selection of the M-41 Walker Bulldog to be built under licence as a replacement for the M-24. It was fitted with the same 77mm as the Comet and Echidna and a TD version armed with the 20pdr was developed, which was subsequently upgraded with the L7 105mm (modified with muzzle brakes etc.) that replaced the M-10, M-18 and eventually the M-36. The M-44 was adopted as the replacement for the Yerumba and the M-42 Duster was introduced as well. It was also developed into a ATGW carrier for Malkara, while the M-75 APC was also introduced and built in some numbers.
Phase 6 is fantasy realm, the Universal Tank I choose is the Conqueror 😉
Phase 7, the Centurions are modernised with improved armour, L7 and possibly diesel engines to supplement and partially replace the Comet in the CMF.